The state Environmental Hearing Board has rejected a 3-year-old complaint from a group of local residents claiming that the Department of Environmental Resources abused its authority in approving the proposed UGI Devonshire housing development in Salisbury Township.

A township official said the action removes one obstacle to completion of the long-delayed development. But neither he nor a UGI spokesman contacted late yesterday could say if or when construction of the project will begin.

The residents maintained that DER's approval of a revision to the township's "official sewage facilities plan" to accommodate UGI violated state law, because the development will contribute to existing overflow problems in the sewage system.

They also contended DER failed to follow a constitutional mandate to assess the environmental impact of the proposed development.

The proposed development involves 351 single-family house lots on 141 acres between Hess's department store on Lehigh Street and Allentown's Lehigh Parkway.

"The evidence established that the surcharging problem will be corrected by the time UGI's development is built," according to the decision of Anthony J. Mazullo Jr. of the environmental hearing board.

He also wrote: "The environmental impact of UGI's proposed development will be minimal, especially when compared to the benefits which will be derived from it."

"Anyone driving by that area will see what devastation will take place," countered Janet Keim of Salisbury, one of the residents who had appealed to the state hearing board.

She said she was disappointed by the board's decision, but added: "When you're fighting big money, decisions like that do not surprise me."

Keim is chairman of the Salisbury Township commissioners but said she was involved in the legal appeal as a private citizen.

She said the hearing board's decision "undermines people's confidence in their own laws that are made to protect them. Every resident and sportsman in this area should take a good look at whether or not our agencies are doing the job of protecting the environment that they are paid to do."

In addition to sewage, other issues addressed in the board's 23-page decision have to do with residents' concerns about erosion, storm water management, adequacy of water supply, impact on local traffic, impact on historic and archaeological sites, and aesthetic and visual impacts of Devonshire.

The hearing board decision states "the record demonstrates that DER and the township thoroughly reviewed the potential environmental impact of the development and that UGI agreed to take many measures to minimize this environmental impact."

"We're certainly pleased that the environmental agency has removed this obstacle that will enable us to move ahead with the project," said a UGI spokesman at the company's headquarters in Valley Forge yesterday. But he could not say when work will begin at the property in the township.

UGI's Devonshire development has been proposed for nine years. UGI lawyers and staffers more familiar with the controversial project could not be reached late yesterday to comment on its future.

James Morrissey, assistant township manager, said the hearing board case involving sewage was one of the reasons why the Devonshire project has been stalled. He added: "I don't know if this means UGI is going to move ahead. The thing only UGI can answer is what are they are going to do next."

Morrissey said when the township gave the Devonshire project final approval a few years ago, it attached a number of conditions to that approval. He said the developers still have to meet other conditions, though he declined to elaborate.

The township revised its sewage plan so it can extend the municipal sewer system to the development in 1979 and DER approved the revisions in 1980.

Mazullo of the hearing board said DER has the authority to require revisions of municipalities' sewage facilities plans.

According to Mazullo's decision, the development will generate 70,000 gallons of sewage a day when it is completed - which he said would take seven years. He said that is 1 percent of the capacity of a city sewer line the sewage will flow into.

He said projects to end sewage overflows into Little Lehigh Creek early this year - will be completed long before that time.

The appeal to the hearing board was filed on Oct. 18, 1982 by Keim and her husband Floyd, the Alton Park Homeowners' Association of Allentown, the Salisbury Association, and the following other residents: William and Mary DeWalt of Allentown, plus Douglas and Cynthia Sherly, Dale and Margia Smith, John and Margie Thomas, Walter and Shirley Wilson, Richard and Sandra D'Agostino, Allan and Evelyn Dicks, and James and Penelope Pantano - all of Emmaus.

Six days of hearings were held in the summer of 1983. UGI, which is based in Valley Forge, intervened in the case.

Keim said the residents had not been informed of the hearing board's decision, which was made Tuesday. She noted the decision could be appealed but could not say if it will be.